Fluorinated peroxides

ABSTRACT

1. A PEROXIDE HAVING THE FORMULA   M-O-C(-RF)(-RF&#39;&#39;)-O-O-C(-RF)(-RF&#39;&#39;)-O-M   WHEREIN M IS AN ALKALI METAL AND RF AND RF&#39;&#39; ARE INDEPENDENTLY FLUOROPERHALOALKYL RADICALS HAVING THE FORMULA -CF2(CFX)NX WHEREIN X IS FLUORINE OR CHLORINE AND N IS 0 TO 5.

Un ted State Patent 3,839,462 FLUORINATED PEROXIDES L. Ray Anderson,Morristown, N.J., William B. Fox, Alexandria, Va.,' and Frederick J.Gefri, Irvington, N.J., assignors to Allied Chemical Corporation, NewYork, N.Y. No Drawing. Filed Jan. 12, 1972, Ser. No. 217,232

. Int. Cl. C07c 73/00 US. Cl. 260610 R 14 Claims tiators for thepolymerization of olefins, especially fluoroolefins.

In accordance with this invention, novel peroxides having the formulawherein M is an alkali metal and R, and R, are independentlyfluoroperhaloalkyl radicals having the formula -CF (CFX),,X wherein X isfluorine or chlorine and n is 0 to 5, are prepared by reacting, undersubstantially anhydrous conditions, an alkali metal peroxide with afluoroperhalo ketone 0f the formula R;R;'C=O, as represented by thefollowing equation:

In the preferred embodiments of this invention, M is lithium, sodium orpotassium, preferably sodium; X is fluorine; and n is 0 or 1. Inespecially preferred embodiments, R, is trifluoromethyl and R, istrifluoromethyl or chlorodifluoromethyl, preferably trifluoromethyl.

The reaction is conveniently carried out at room temperature. Ifdesired, however, the reaction can be carried out at temperatures aboveor below room temperature, such as, for example, from about 0 C. to 50C., preferably 0 C. to 40 C.

The reaction is conveniently carried out under autogenous pressures,ranging from about 50 to 150 p.s.i.g., but the reaction pressure is notespecially critical.

The reaction can be carried out in the absence of other materials, butit is desirable to carry out the reaction in the presence of an inertliquid diluent, preferably a diluent which is a solvent for the product.The product is soluble in polar organic solvents, such as acetonitrile.

The reactants may be addedto the reaction mixture in any order and inany desired proportion. However, it is desirable to use a slight excessof the fluoroperhaloketone to ensure complete reaction with the alkalimetal peroxide. The product is then conveniently recovered as a solid byevaporation of the reaction mixture to remove unreactedfluoroperhaloketone and the diluent, if any.

The novel peroxides of this invention are useful to initiatepolymerization of olefins, especially fluoroolefins, such as, inparticular, fluoroperhalo-alpha-olefins having 2 to 5 carbon atoms,e.g., tetrafluoroethylene and chloro- V trifluoroethylene. Except forthe use of a peroxide of this invention as the initiator, thepolymerization is carried out in accordance with conventional methodsfor polymerizing such olefins in the presence of a catalytic amount of afree radical initiator. Typically such methods comprise polymerizing theolefin in an aqueous medium at a temperature of from about 0 to C. and apressure of from 15 to 500 p.s.i.g. The aqueous medium is usuallybuffered to a pH between 7 and 11. The peroxides of this invention areemployed in a catalytic amount sufiicient to initiate polymerization.Preferably this amount corresponds to a concentration of from about 0.1to 2.0 percent by weight in the aqueous medium.

EXAMPLE 1 A substantially anhydrous reaction mixture consisting of about20.8 grams mmoles) of hexafluoroacetone and 3.9 grams (50 mmoles) ofsodium peroxide in 50 ml. of acetonitrile was stirred in a sealedreactor at room temperature for two days, during which time the solidsodium peroxide dissolved to give a clear viscous solution. Evaporationof the solution under vacuum to remove the acetonitrile and excesshexafluoroacetone left a white solid product, which was identified bymodern analytical techniques as having the formula The product wassoluble in water, acetonitrile and other polar organic solvents, but notin nonpolar organic solvents. It was strongly oxidizing toward K'I.

The approximate half-life values for NaOC (CF OOC(CF ONa at varioustemperatures and pH values were determined iodometrically to be asfollows:

Tempera- Half-life, pH ture, 0. hours EXAMPLE 2 Tetrafluoroethylene waspolymerized at 25 C. and 300 p.s.i.g. in a buffered (pH=9.5) mediumcontaining 0.5 percent by weight of NaOC(CF OOC(CF )-ONa.

EXAMPLE 3 Chlorotrifluoroethylene was polymerized at 0-5 C.

and 75 p.s.i.g. in a buffered (pH:=9.5) aqueous medium containing 0.5percent by weight of NaOC(CF OOC(CF ONa We claim: 1. A peroxide havingthe formula 1 I M00 0 0310M II R! 7. A peroxide having the formulaNaOC(CF 0OC(CF ONa 8. A process for preparing a peroxide having theformula MooooooM wherein M is an alkali metal and R and R areindependently fluoroperhaloalkyl radicals having the formula CF (CFX) Xwherein X is fluorine or chlorine and n is 0 to 5, which processcomprises reacting at a temperature in the range of about 0 C. to 50 C.,under substantially anhydrous conditions and autogeneous pressures, analkali metal peroxide with a fluoroperhaloketone having the formula RR;C=O wherein R; and Rf are as defined above.

9. The process of claim 8 wherein the alkali metal peroxide is lithiumperoxide, sodium peroxide or potassium peroxide.

10. TThe process of claim 8 wherein X is fluorine.

11. The process of claim 8 wherein n is 0.

UNITED STATES PATENTS 2,568,682 9/1951 Levesque 260610 R 3,047,406 7/1962 Ferrani 260-610 R 3,235,584 2/1966 Blumberg 260-610 R BERNARDHELFIN, Primary Examiner W. B. LONE, Assistant Examiner US. Cl. X.R.26092.1

1. A PEROXIDE HAVING THE FORMULA